JP2023524883A - System and method for high resolution negative 3D printer - Google Patents

Abstract

A system and method for fabricating solid three-dimensional objects from liquid polymeric materials at high resolution. laser ablation to leave a negative image of the layer to be printed, which is then brought into engagement with existing portions of the object being fabricated and exposed to a non-digital UV curing light source. Because the only part of the digitization is material removal, and this part is done with a laser, the speed of printing and robustness of the manufacturing process are vastly improved over conventional additive or 3D fabrication techniques. [Selection drawing] Fig. 2

Description

(Cross reference to related applications)
This application claims priority to US Provisional Patent Application No. 62/704,446, filed May 11, 2020.

(Technical field)
The present invention relates to methods and apparatus for fabricating solid three-dimensional objects from liquid polymeric materials at high resolution.

In conventional additive or three-dimensional manufacturing techniques, building a three-dimensional object is done layer by layer. Layer formation is carried out by solidifying the photocurable resin under the action of visible or UV light irradiation. Two techniques are known, one for forming a new layer on the top surface of the growing object and the other for forming a new layer on the bottom surface of the growing object.

When forming a new layer on top of the growing object, after each irradiation step, the object being built is lowered into a resin "pool", a new layer of resin is applied to the top surface, and a new irradiation is applied. step is performed. Examples of such techniques are presented in Hull, US Pat. No. 5,236,637. A disadvantage of such "top-down" techniques is that the growing object must be submerged in a deep pool of liquid resin and the exact coating layer of liquid resin must be reconstructed before forming the next layer of the object. That is.

When forming a new layer on the bottom of the growing object, it is necessary to separate the object being built from the bottom plate in the fabrication well after each irradiation step. Examples of such techniques are presented in Hull, US Pat. No. 5,236,637. Such "bottom-up" techniques have the potential to obviate the need for deep wells in which objects are submerged, by instead lifting objects from relatively shallow wells or pools, but such techniques are not commercially viable. A problem with conventional "bottom-up" fabrication techniques is that when separating the solidified layer from the bottom plate, due to the physical and chemical interactions between them, great care must be taken and no additional mechanical elements are required. It means that it must be adopted. For example, US Pat. No. 7,438,846 uses an elastic separation layer to achieve "non-destructive" separation of solidified material at the bottom build surface. Another approach employs a sliding build plate, for example, as shown in US Pat. No. 9,636,873. Such approaches complicate the apparatus, make the process time consuming, and/or introduce mechanical steps that can potentially distort the product.

A continuous process for manufacturing three-dimensional objects has been proposed in considerable detail in terms of a “top-down” technique in US Pat. No. 7,892,474 and the best approach to date is provided by WO2014/126837 there is There, an interface is formed between first and second layers or zones of the same polymerizable liquid. A first layer or zone (sometimes referred to as a "dead zone") contains an inhibitor of polymerization (at least in an amount that inhibits polymerization), and in a second layer or zone, polymerization is no longer substantially inhibited. To the point where the inhibitor is depleted (or otherwise not incorporated or permeated therein). The first zone and the second zone do not form a strict interface between each other, but rather a gradient of composition between them, which can also be viewed as an interphase formation, as opposed to an abrupt interface. exists, which means that the phases are miscible with each other and between them (also between the three-dimensional object being fabricated and the build surface onto which the polymerizable liquid is irradiated) (partially or completely ) because it creates a gradient of polymerization.

U.S. Pat. No. 5,236,637 U.S. Pat. No. 7,438,846 U.S. Patent No. 9636873 U.S. Pat. No. 7,892,474 WO2014/126837

Despite its promise, this technique has several limitations. First, it can only be used for one material formulation at a time, greatly limiting the physical properties of the articles that can be produced with this technique. Second, the production rate is limited by the inhibitor used, liquid phase viscosity, and UV light source power. Additionally, the article is still submerged in the resin bath and needs to be washed at the end of the process to remove any residue.

In view of the aforementioned limitations of current additive or three-dimensional ("3D") manufacturing techniques, the present invention provides the ability to create, on film, the next layer of the article being fabricated at high resolution so that the film and article have the same It provides a much faster method for manufacturing three-dimensional articles by exposing them to corresponding light sources while in contact with the formed portion to produce subsequent layers of the formed article. Because this is a continuous sequence manufacturing process, it increases the speed and versatility of forming articles compared to other techniques. Multiple materials can be introduced at each layer and no cleaning is required at the end of the manufacturing process.

In one embodiment, new methods of 3D printing are provided that reduce waste and increase manufacturing speed. Material is applied non-digitally onto film, excess material is digitally laser removed, and then a complete image is taken of an existing portion of the object being fabricated (also referred to herein as a "sample"). and exposed to a non-digital UV curing light source. Because the only part of the digitization is material removal, and this part is done with a laser, the speed of printing and robustness of the manufacturing process are vastly improved over conventional additive or 3D fabrication techniques.

One of the most suitable materials for this technique is a high viscosity material that will not move between the material injection unit and the sample building unit, but as the material viscosity decreases the final resolution of the sample during manufacture also decreases. Any material can be used as long as it degrades.

One embodiment of a negative tone 3D printing system constructed in accordance with the present invention includes a film and roller-based application system, a laser injection system positioned on top of a material recycling unit, and the film being exposed to the sample during UV curing. Contains contacting sample build units. Another optional unit is a sample stripping unit that can operate using mechanical, chemical, or optical (eg, laser) means, or any combination of these approaches.

The application system can be implemented in any of several ways. For example, in one embodiment, the coating system can include a syringe with a film forming unit through which the coated film passes between two rollers. Other coating techniques that can be used can include conventional screen printing, dispenser unit(s) printing, micro gravure coating, slot die coating, inkjet printing, or roller coating.

Application can be done in a controlled environment, in some embodiments in a closed loop, to prevent evaporation or oxidation of the solvent, for example, and to minimize material waste for later reuse. It can be implemented, where the material applied onto the film passes through a recycling unit, with each cycle adding a small amount of material to the previously unused portion.

The application system can optionally support multi-material 3D printing.

A negative working digital laser projection system can include a pulsed laser with sufficient energy to project a negative image of the material from the film surface. Lasers that can be employed for such purposes can include infrared (IR) lasers, ultraviolet (UV) lasers, carbon dioxide (CO ₂ ) lasers, and the like.

The film used for material transfer, with or without a coating on the film, should be a transparent film, at least transparent (or nearly so) to the wavelength of the laser used. Examples of transparent films that can be used are polyethylene terephthalate (PET), biaxially oriented polypropylene (BOPP), polyimide (PI), and the like.

Film coatings are used to enhance material injection from the film into the material recycling system. To that end, metal or other polymer coatings with additives that absorb at the laser wavelength and create areas that are digitally transparent upon exposure to a negative laser emission system can be used.

As mentioned above, the list of materials that can be used for 3D printing with this system is very wide and it is impractical to list all possible materials in detail. By way of example, possible materials include UV curable monomers and polymers, viscose or sensitive materials, acrylates, epoxies, urethanes, adhesives, pastes, etc., and additives such as ceramics, metals, organic additives, fiber reinforcements, etc. UV curable monomers and polymers with UV curable waxes, or UV/visible light curable material formulations with UV curable waxes.

The system can be used for low or high viscosity light curable or partially curable materials, ceramic and metal pastes, solder pastes (epoxy or urethane), with or without UV curable ends. It can also be used for materials that cure with heat, such as silicone-based materials) or silicone-based materials. Reactions can proceed by light, by heat, by other catalysts (Pt, OH, etc.), or by a combination of these mechanisms.

The system can also be used for 3D printing of sensitive materials, for example 3D printing of biocompatible materials. It can also be used for 3D printing of thermoplastic materials at room temperature or high temperature (with some adjustments).

The curing system used in embodiments of the present system is not a digital process and therefore borderline curing means may be employed. For example, it is possible to use UV or visible light curing systems, as well as IR or other thermal curing systems (as post-treatments). It is also possible to use chemically latent catalysts for the curing reaction.

As an example, basic UV formulations combine monomers and polymers such as acrylates, epoxies, urethanes, and other UV or photosensitive materials with a photosensitive initiator or/and coinitiator or sensitizer, such as acetophenone. , thioxanthones, phosphine oxides, iodonium and sulfonium salts, and the like.

The configuration of the sample release system can depend on the chemistry of the film, involve some laser ablation or cleaning of the top surface after curing, and/or be a mechanical system. Any of a number of approaches can be used, such as a system that provides a low angle peel toward the Y axis (e.g., by moving the film away from the sample at a small angle), or two Z axes. , one that provides an axis for the frame (which holds the film) and one for the sample, or a system that provides acoustic vibrations to peel the film from the sample.

These and other embodiments of the invention are described in detail below.
The invention is illustrated, by way of non-limiting example, in the figures of the accompanying drawings.

1 illustrates, in schematic form, an embodiment of the present invention comprising the steps of applying material to a film, removing excess material into a collection system, and then removing the applied film from a sample. and exposure to a non-digital curing system (UV or heat based) while in contact with the substrate, thereby reducing waste and eliminating the need for support materials. 1 is a schematic diagram of a system constructed in accordance with one embodiment of the present invention, focusing on the application process, negative printing with a material recovery unit, and curing during contact with a sample, and an optional sample stripping unit; FIG. It is shown. 3 illustrates aspects of a process according to embodiments of the present invention, including a material negative injection process; 3 illustrates aspects of a process according to embodiments of the present invention, including a material negative injection process; 3 illustrates aspects of a process according to embodiments of the present invention, including a material negative injection process; 4 illustrates aspects of a process according to embodiments of the present invention, including an optional initial curing process; 4 illustrates aspects of a process according to an embodiment of the invention, including a sample contacting process; 4 illustrates aspects of a process according to an embodiment of the invention, including a sample contacting process; 3 illustrates aspects of a process according to embodiments of the invention, including a curing process; 3 illustrates aspects of a process according to embodiments of the invention, including a stripping process; 3 illustrates aspects of a process according to embodiments of the invention, including a stripping process; 3 illustrates aspects of a process according to embodiments of the invention, including a stripping process; FIG. 2 illustrates aspects of a process according to embodiments of the present invention, including a sample surface cleaning process; FIG. 3 illustrates aspects of a process according to embodiments of the present invention, and shows results and structures as a whole. 3 illustrates aspects of a process according to embodiments of the present invention, and shows results and structures as a whole. 1 shows an example of a system constructed in accordance with the present invention, comprising reels and rollers for applying material onto a film, moving the film through a laser firing unit, and sample contact during exposure to UV light for curing. . FIG. 5 shows another example of the system shown in FIG. 4, with several layers printed. FIG. 6 shows yet another example of the system shown in FIG. 4, with several layers printed and optional support material added between the layers. 4 shows yet another example of the system shown in FIG. 4, in which several layers are printed and includes a support material application system configured for injecting support material. FIG. 11 illustrates aspects of an embodiment of the present invention wherein multiple materials are used during printing prior to contact with the sample; FIG. FIG. 11 illustrates aspects of an embodiment of the present invention wherein multiple materials are used during printing after contact with the sample; FIG. Fig. 3 shows an aspect of an embodiment of the present invention, printing uses anti-stick foil to prevent sample distortion during the curing process. FIG. 10 illustrates an aspect of an embodiment of the present invention, printing uses anti-stick foil to prevent sample distortion during the sample peeling process. FIG. Fig. 3 shows aspects of an embodiment of the present invention wherein printing includes using a mechanical detachment system that allows for fast and accurate sample builds; FIG. 10 illustrates aspects of an embodiment of the present invention, printing includes using a material recovery system to reduce waste of excess material during sample building; FIG.

The present invention relates to methods and apparatus for fabricating solid three-dimensional objects from liquid polymeric materials at high resolution. In one embodiment, a system constructed in accordance with the present invention includes the steps of lasering at high resolution a negative image of a film initially coated with a polymerizable liquid, and applying the image to a corresponding light source during contact between the film and the sample. to produce the next layer of the sample. Because this is a continuous sequence manufacturing process, it increases the speed and versatility of forming 3D objects compared to conventional 3D printing processes. However, before describing the invention in detail, it is helpful to present an overview thereof. FIG. 1 provides such an overview, showing some components of a system 100 constructed in accordance with the present invention: step 10 for applying material to film and step 12 for removing excess material into a collection system. , exposing the coated film to a non-digital curing system (UV or thermal based) 14 while in contact with the sample.

By dealing with the negative image of the desired image, some important basic features of the invention become apparent. First, the surplus of material resulting from the application process can be reused and no significant waste is generated during the sample construction process. Second, no support material is required (although the use of a support material remains an option, as discussed below). During curing and contact, the negative image is supported on its upper surface by the film, eliminating the need for a support material in most cases. Some structures may require or benefit from additional support, and the present invention allows for such options. Third, systems constructed in accordance with the present invention have the ability to print at very high speeds because injection and shaping are done in two different areas and the processes can occur simultaneously. The main constraint on printing speed is either the curing process or the negative printing time, but the timing of these individual processes is not additive, i.e. the additive combination of curing time and negative printing time as a whole print speed is not limited. Also, because the curing process is not digital, the UV light source used for curing is less constrained than traditional 3D printing processes.

The negative printing unit can be a laser assisted deposition/laser dispensing system with a pulsed laser having sufficient energy to project a negative image of the material from the film surface into the collection unit. The laser can be UV, IR, _CO2 , or some other laser.

If the printing unit is a laser-assisted deposition/laser dispensing system, a uniformly coated substrate plays an important role in system robustness. An additional coating system is therefore added before the printing unit. The coating system can be a conventional coating system such as a coating system based on a microgravure coater or a slot die coater or a roller coating system. It can also be an application system based on screen printing, a dispenser or an inkjet system. In one embodiment of the invention, the application system can be based on a syringe and gap system as shown in FIG. In such a system 400, a material 402 is dispensed from a syringe 404 onto a substrate 406 (eg, by an air or mechanical pump that drives the material from the syringe onto the substrate) and the applied substrate 408 is , is moved (eg, by a motor-driven roller or other actuator) toward and through a well-defined gap 410 . The gap may be defined by a blade or other type of barrier, as shown in FIG. 4, or by two cylinders (eg, rollers) placed close together.

After passing through the gap 410, a uniform layer 412 of material is formed on the substrate and a laser assisted deposition/laser dispensing system 414 can inject material from the coated substrate to a material recovery system. Coated substrate 416 moves from laser-assisted deposition/laser dispensing system 414 to curing station 418 and contacts receiving substrate 420 in the presence of UV light and/or heat, thereby curing the article being fabricated. Cure the material for the new layer of

In other embodiments of the present invention, the coating system can include a screen printing module, where the material is coated using a blade or squeegee onto a screen or stencil of film with well-defined holes. and the material is transferred to the substrate in soft or hard engagement. Alternatively, the application system can include a dispenser or inkjet head for printing the material onto the carrier substrate. Alternatively, the application system can be a gravure or microgravure system that applies a highly uniform layer of material to the substrate. In yet another embodiment, the application system can be a slot die system that applies a highly uniform layer of material to the substrate. Alternatively, the coating system can be a roller coating system that applies a highly uniform layer of material to the substrate.

In any of these and/or other embodiments of the invention, the coating system is placed in an enclosed compartment with a controlled environment (temperature, pressure, etc.) to prevent solvent evaporation from the print material. Or the oxidation of the material can be prevented, thereby extending the pot life of the material.

In some embodiments of the invention, the application system contains two or more materials. This creates the possibility of printing multiple materials onto an intermediate substrate (e.g., a film such as substrate 406 in FIG. 4) in a controlled sequence to allow for a final substrate (e.g., the receiving substrate in FIG. 4). It is possible to print more than one material on material 420).

In one embodiment of the invention, the intermediate substrate of the coating system is translatable forward and backward (in terms of applying material to the intermediate substrate) in a controlled manner while increasing the gap between the coater rollers. Yes, giving the possibility of recoating the same area of the intermediate substrate multiple times with printing material without contamination of the roller. Also, such a process reduces (or eliminates) the amount of intermediate substrate consumed during the initial printing process, preventing waste.

In some embodiments, after the current uniform layer of material applied on the intermediate substrate has been consumed (completely or partially) by printing in the printing unit, the intermediate substrate is ready for the next printing process. To do so, one can loop back to the coating system for recoating or translate back to the coating system to apply a new uniform coating layer.

The film (or other intermediate substrate) used for printing can be a substrate transparent to the laser wavelength, with or without a metallic (or other) coating. Examples of such films (substrates) are PET, BOPP, PI and the like. This film can be coated with a metal or polymer coating with additive(s) that absorb at the laser wavelength and create areas that are digitally transparent upon exposure to a negative tone laser firing system.

Among the printing materials that can be used in systems constructed in accordance with the present invention are any liquid or paste materials. However, the advantage of the system of the present invention exists primarily when highly viscous materials are employed that otherwise cannot be properly printed at high resolution. For example, UV light/visible light curable material blends and UV curable monomers and polymers of viscose or photosensitive materials can be printed using a system constructed according to the present invention. Other materials that can be printed with a system constructed in accordance with the present invention are acrylates, epoxies, urethanes, adhesives, pastes, or inks using either UV curing or heat curing. Still other materials that can be printed with systems constructed in accordance with the present invention are UV curable monomers and polymers, including additives such as ceramics, metals, organic additives, fiber reinforcements, and the like. Also UV curable waxes, low or high viscosity materials that cure or even partially cure with light, reactions initiated by heat or other catalysts (Pt, OH, etc.) with or without UV curable ends Epoxy-, urethane-, or silicone-based materials, ceramic and metal pastes, and solder pastes, biocompatible materials, and thermoplastic materials (at room temperature or at elevated temperatures by adjusting the ambient temperature) are all suitable for use in the present invention. can be printed on a system configured according to Possible basic formulations and mechanisms involve combining monomers and polymers of acrylates, epoxies, urethanes, or other UV or photosensitive materials with photosensitive initiators such as acetophenones, thioxanthones, phosphine oxides, iodonium and sulfonium salts. agent or/and co-initiator or sensitizer.

FIG. 2 shows a system 200 configured according to one embodiment of the invention. In this system, a material 202 is first dispensed onto a transparent substrate 204 by an application system 206, such as one using a syringe and gap system as described above. The material-coated substrate 208 is fed to a negative printing unit 210 where excess material (i.e., the portion of the coating material not applied to the sample) is removed from the coated substrate (e.g., by laser irradiation). ) creates a negative image of the layer applied to the sample. As shown, this excess material can be collected by material recycling system 212 and returned to application system 206 for recycling. As shown, the material 214 that remains on the applied substrate is fed to a curing system (eg, a UV curing system) 216 and/or an imaging system to UV cure and/or dry during contact with the sample 220. We will soon arrive at a sample build unit 218 that can use the . Curing/drying while the material is in contact with the sample (i.e., the previously formed portion of the article being manufactured that is placed on the receiving substrate 222) causes subsequent layers of the sample to form thereon. printed directly to the A sample release system 224 then effects release of the sample 220 from the carrier substrate 204 .

Figures 3a-3m detail the various steps involved in the overall printing process. Referring first to FIG. 3a, a negative injection process 300 is shown. A layer of material 302 is applied onto an intermediate substrate (eg, film or foil) 304 . A laser 306 is used to project a negative of the image (of the next layer printed on the sample) from the coated substrate, utilizing the laser absorption properties of the material or of the metallized film. The injected material 308 is collected (310) in a material recovery unit 312 (or units if multiple materials are used), which can be reused later (FIGS. 3a and 3b). Only a segment of image material 314 remains on film 304 for further use (Fig. 3c).

Optionally, the image material 314 on the film can be exposed to low power UV light 316 or temperature prior to contact with the sample, as shown in Figure 3d. Since some materials, primarily liquid materials, require a high-definition image material boundary prior to such contact, e.g., to avoid severe reduction in print resolution, this procedure allows the material image 314 to be The boundaries of the parts can be clearly defined. In such a process, the UV partial curing station 318 places an inert gas (eg, Ar, CO ₂ , He, Ne, etc.) into the workspace 324 where UV light 326 from the UV light source 316 is incident on the material layer 314 . ) 322 can be included. Inert gas enters through one or more gas inlets 328 and exits through diffuser 330 toward working space 324 . A gas pressure homogenizer can be used to ensure constant pressure throughout the system.

Preferably, the intermediate substrate 304 is coated with a thin metal foil, eg a 20 nm thick Ti layer. The layer of metal foil, if present, will substantially reduce the transmission of UV light 326, ensuring that only the edges of material layer 314 near the contact area with intermediate substrate 214 are cured or partially cured. . As an example, a 20 nm thick Ti layer transmits approximately one tenth of the UV light 326 that the unprotected areas of the intermediate substrate 314 transmit. In areas where the metal foil has been removed, such as by laser ablation or other process, the UV light 326 will impinge on the edges of segments of the material layer 314, again only those edges are cured or cured. Partial curing is guaranteed. As an additional precaution to prevent unwanted or over-curing of segments of material layer 314 , gas diffusion system 320 is non-reflective so that UV light 326 is not reflected toward segments of material layer 314 . Can be made of material.

The presence of inert gas 322 pumped through the diffuser purges any oxygen from working space 324 . The thickness of this working space area is related to the gas pressure as it is forced through diffuser 330 . While maintaining the segments of material layer 314 in regions of the oxygen-purged workspace, the UV curing system then exposes the bottoms and edges of these segments to UV light 326 from UV light source 316 . Harden.

Figures 3e and 3f present views before and after contact between the film 304 (ie, the segment of coating material 314 on the film) and the sample, while Figure 3g shows the UV exposure and shaping of the sample. At this stage, either UV exposure or exposure to elevated temperature can be used to achieve material transfer to the sample (in such cases a coated polyimide film such as Kapton can be used). As shown, the film 304 is brought to the area where the receiving substrate 334 resides, bringing the receiving substrate (or existing layer of sample, if present) into contact with the segment of coating material 314 on the film. (eg, by lifting the receiving substrate present). The segment of coating material 314 is then cured by exposure to UV light 336 from UV light source 338 . This may be the same UV light source as described above or a different UV light source. Exposure to UV light 336 (and/or heat) cures the segment of applied material to form a segment of a new layer 340 of the sample (ie, the object under construction).

After curing, the sample remains bonded to film 304 (via segments of newly cured layer 340). Therefore, it is preferable to provide a peeling mechanism. Therefore, as shown in Figures 3h-3j, the metal coating of the film 304 remains under the just-cured material and can be used for laser wavelength absorption and sample release, so the laser itself (used for negative printing) 306 can be used as a sample stripping unit. A laser 306 illuminates the locations where segments of the newly cured layer 340 exist, enabling such separation. The laser can also be used to remove metal residue 342 from the sample that may have come off the film 304 during sample peeling (Fig. 3k), leaving a clean hardened layer 340 present on the sample (Fig. 3l). ). The result 350 of printing several layers 340 is shown in Figure 3m.

FIGS. 4-7 show configuration examples of systems for carrying out the method of the present invention. In one embodiment of the invention, only one layer is printed with only one material supplied. FIG. 4 shows such an arrangement. Material 402 is applied onto film 406 , laser system 414 removes the negative image, and multiple samples 420 are moved into contact with film 406 in sequence. The material 416 hardens on contact and the new sample replaces the old sample.

FIG. 5 shows a 3D version of the configuration shown in FIG. In this case, the same sample 520 is repeatedly contacted with the film 406, each time adding (printing) a new layer 522a, 522b, etc. to the sample. Curing takes place while the top of the sample is in contact with the material of the new layer 524 on the film. However, it should be noted that transfer from the film to the sample will not occur if there is no direct contact between the material on the film and the sample. Transfer therefore depends on the area of each unit of material on the film and the surface structure of the sample.

One way to overcome this problem is to add a support material 602 that contacts the film 406 and thus will transfer all the material 524 on the film to the sample. FIG. 6 shows how a support material 602 is used to collect all material from the film to the sample.

FIG. 7 illustrates the use of option unit 702 for 3D negative printing with support material. Optional unit 702 mechanically injects support material 704 (eg, via syringe 706) to even out the sample height that will be in contact with film 406 during curing. The sample 520 moves back and forth between a curing position 710 and an interlaminar support injection position 712 .

A more advanced configuration of systems configured in accordance with embodiments of the present invention relates to multi-material 3D printing. In such cases, multiple application units may be arranged to supply different materials to the transfer film(s), apply the different materials to the film(s), and apply a negative image for each material to the film(s). and the material is brought into contact with the sample and transferred to it. 8A-8B show views of a substrate 802 containing a second material 804 and a sample 334 already having the first material 314 before and after contact. Negative images of different materials are compatible and can coexist in the same layer.

The film itself can be a transparent anti-stick foil. For example, PTFE or PFE or other anti-stick foils can be used to ensure easy release of the sample from the film after curing. 9a-9b show views before and after the peeling process based on the anti-stick properties of the film 902. FIG. This approach to sample detachment may be complementary to the laser detachment mechanism described above, or may be the only detachment mechanism used.

Yet another approach to sample detachment can be primarily mechanical. FIG. 10 shows a mechanical stripping system 1002 that can work with or without the stripping mechanism described above. Any of a number of mechanical approaches can be used. For example, a low angle peel toward the “Y” axis can be used by moving the film 406 away from the sample 1004 at a small angle. Alternatively, two Z axes can be used, one for the frame (which holds the film 406) and one for the sample 1004. FIG. Another approach would be to use acoustic vibration to peel the film 406 from the sample 1004 .

FIG. 11 illustrates one additional feature of systems constructed in accordance with embodiments of the present invention, material recycling system 1102 . To reduce waste, negative image printing can be done above a tray or other transport that collects unused material and reinjects it into the coating unit 1104 .

Not shown in the above figures are the unit or units that control the operation of the various systems. Those skilled in the art will appreciate that such units, often referred to as controllers or similar names, provide signals to elements of the coating system, the negative printing unit, the material recycling system, the curing system(s) and the sample stripping system. It can be understood to be a processor-based unit programmable to perform the processes described above by issuing a command. Optionally, these signals activate end effectors, rollers, lasers, UV or IR illumination/heating systems, and other elements to perform the tasks described above. Such controllers generally include a processor(s) executing computer readable instructions (i.e., computer programs or routines) that define the methods described herein, which are non-transitory computer readable embodied and executed on a medium; Such processes may be expressed in any computer language and executed on any suitable programmable logic hardware. A processor-based controller on which or with which the method of the present invention can be practiced will typically include a bus or other communication mechanism for conveying information and a a main memory such as a RAM or other dynamic storage device coupled to the bus for storing instructions to be executed by the processor and for storing temporary variables or other intermediate information during the execution of instructions to be executed by the processor; and a ROM or other static storage device connected to the bus for storing instructions for the processor. It may also include storage devices such as hard disks or solid state drives and may be connected to the bus for storing information and instructions. The target controller may optionally include a display connected to the bus for displaying information to the user. In such cases, input devices including alphanumeric and/or other keys may also be connected to the bus for communicating information and command selections to the processor. Other types of user input devices, such as cursor control devices, may also be included and connected to the bus for communicating directional information and command selections to the processor and for controlling cursor movement on the display. can.

The controller may also include a communication interface connected to the processor that provides bi-directional wired and/or wireless data communication with the controller, eg, via a local area network (LAN). . The communication interface sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information. For example, a controller may be networked with a remote unit to allow data communication to a host computer or other device operated by a user. Accordingly, the controller can exchange messages and data with the remote unit, including diagnostic information to assist in troubleshooting errors, if desired.

Thus, a method and apparatus for fabricating solid three-dimensional objects from liquid polymerizable materials at high resolution are described.

200 System 202 Material 204 Transparent Substrate 206 Application System 208 Material Applied Substrate 210 Negative Printing Unit 212 Material Reuse System 216 UV Curing System 218 Sample Build Unit 220 Sample 222 Receiving Substrate 224 Sample Release System

Claims (20)

1. A system comprising a printing and coating unit configured to apply a uniform layer of material to a substrate and to feed the coated substrate to a negative printing unit, the negative printing unit for applying the coated substrate. configured to remove excess material from a workpiece and provide a resulting version of the coated substrate having residual segments of the material to a sample build unit, the sample build unit being configured to produce a layer of the article being fabricated; A system configured to engage the coated substrate having the residual segment of the material representing an image with a sample and to cure the residual segment of the material during contact with the sample. The coating system includes
It is configured to apply said material with a blade or squeegee onto a film screen or stencil with well-defined holes and to transfer said material to said substrate with soft or hard engagement. a screen printing module;
a dispenser configured to print the material onto the substrate;
an inkjet head configured to print the material onto the substrate;
a gravure or microgravure system configured to apply said uniform layer of said material to said substrate;
a slot die system configured to apply the uniform layer of the material to the substrate;
a roller application system configured to apply the uniform layer of the material to the substrate;
a syringe of said material and a pump for conveying said material from said syringe onto said substrate, said pump conveying said applied material toward and through a gap between rollers or knives; a syringe and pump that produces the uniform layer of the material on the substrate with a thickness defined by the gap;
2. The system of claim 1, comprising one of: 3. The system of claim 1 or 2, wherein the application system is in an enclosed compartment with a controlled environment. 4. The system of any one of claims 1-3, wherein the application system is configured to apply two or more materials to the substrate. 5. Any one of claims 1-4, wherein the coating system includes a gap and is configured to translate the substrate bi-directionally through the coating system while adjusting the width of the gap. The system described in paragraph. The material may be a polymer material or a mixture of a polymer material and a monomer material, a metal paste, a solder paste, a ceramic paste, a high viscosity material, a low viscosity material, a wax material, a sensitive material, or a material curable with UV light or with heat. 6. A system according to any one of claims 1 to 5, wherein the system is one of 7. The system of any one of claims 1-6, wherein the negative printing unit is a laser-based system configured to eject material of a material recycling system from the coated substrate. 2. From claim 1, wherein the substrate is one of a continuous transparent film substrate, a transparent film substrate coated with a metal layer, or a transparent film substrate coated with a metal layer and a dielectric layer. 8. The system of any one of 7. 9. The system of any one of claims 1-8, further comprising a support material application unit configured to inject support material into contact between the sample and the substrate during curing. applying material to a substrate with a printing and application unit to produce a coated substrate having a uniform layer of material thereon;
conveying the coated substrate to a negative printing unit where excess material is removed leaving an image of the material on the substrate;
in a sample build unit, engaging the material remaining on the substrate and curing during contact with the sample;
method including. Said uniform layer of said material comprises:
An air or mechanical pump is used to deliver a portion of the material from a syringe onto the substrate, translating the substrate toward and through a well-defined gap between rollers or knives. creating said uniform layer of said material with a thickness defined by said gap; applying said material to a screen or stencil of film with well-defined holes; using a blade or squeegee; screen printing modules, dispensers, ink jet heads, gravure or microgravure systems for applying said uniform layer of said material to said substrate, which transfer said material to said substrate in soft or hard engagement; 11. The method of claim 10 produced by one of a slot die system that applies a uniform layer to the substrate, a roller coating system that applies the uniform layer of the material to the substrate. 12. A method according to claim 10 or 11, wherein said uniform layer of said material on said substrate is created in a closed compartment with a controlled environment. 13. A method according to any one of claims 10 to 12, wherein said printing and applying unit applies two or more materials to said substrate. 14. Any one of claims 10 to 13, wherein the printing and coating unit includes a gap through which the substrate is translated bi-directionally while adjusting the width of the gap. described method. The material may be a polymer material or a mixture of a polymer material and a monomer material, a metal paste, a solder paste, a ceramic paste, a high viscosity material, a low viscosity material, a wax material, a sensitive material, or a material curable with UV light or with heat. 15. The method of any one of claims 10-14, being one of 16. The method of claims 10-15, wherein the negative printing unit is a laser-based system having a high frequency laser and the method includes using the laser to inject the material from the substrate into a material recycling system. A method according to any one of the preceding paragraphs. 11. from claim 10, wherein the substrate is one of a continuous transparent film substrate, a transparent film substrate coated with a metal layer, or a transparent film substrate coated with a metal layer and a dielectric layer. 17. The method of any one of 16. 18. The method of any one of claims 10-17, wherein the substrate is roller transported to deliver the image printed by the negative printing unit to the sample build unit. 19. A method according to any one of claims 10 to 18, wherein the image in the material printed by the negative printing unit is cured by UV light or dried by a heater in the sample build unit. 20. The method of any one of claims 10-19, further comprising injecting support material into the sample during curing in a support material application unit.

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